Several smart phones have recently included an integrated ambient temperature sensor. However, the device temperature is not equal to the ambient temperature due to self-heating of the devices. The determination of the ambient temperature is therefore possibly imprecise. In order to improve this, multiple temperature sensors are also integrated into some mobile devices. Multiple temperature sensors in a mobile telephone measure the device temperature at different locations in the device. The ambient temperature is estimated with the aid of the internal temperature sensors and the power consumption (heat) of the device. Even so, uncertainty remains concerning the actual ambient temperature.